I haven't grown them personally, but several people in the local DCTropics group are growing them and report that they are reliably hardy.

If you're interested in growing tropicals, check us out. Gardenweb doesn't accept a direct link to the group, but you can Google "DCTropics" to find us (our group is the first result that pops up).

BTW be sure to check out the "Tropicalesque" forum here on Gardenweb.

Here is a link that might be useful: Tropicalesque forum

Your zone (6B) is colder than DC. I have been trying for several years here in 6B/7A to get one to survive the winter outside so that it will flower - it's one of my favorite scents...

I'll let you know in a few weeks if it worked.